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Detailed test–particle simulations of energetic particles interacting with magnetized plasmas
Get PDFAn important research area in space physics and astrophysics is the transport of energetic, charged particles, such as electrons, protons, and muons, in magnetic turbulence, with active research in this field going back to Jokipii (1966). For example, the magnetic turbulence in the solar wind, arising from the combination of the motion of the solar wind plasma and the Sun's magnetic field, deflects energetic charged particles away from their initial trajectories. These particles may have originated in the Sun (solar energetic particles), or from sources outside the solar system such as supernova remnants (galactic cosmic rays) or active galactic nuclei (extra-galactic cosmic rays). Regardless of their origin, these high energy particles will be deflected in the heliospheric magnetic field, with transport being described by diffusion coefficients parallel and perpendicular to the local mean field. Research over the years has shown that the perpendicular transport needs to be described by theoretical models that are highly non-linear. Test-particle simulations performed using various analytical turbulence models have allowed these theoretical descriptions of particle transport to be improved by providing numerical results to compare with theoretical predictions. In this work, a test-particle code has been developed using a new trajectory solver that allows for better energy conservation and position accuracy. This is then used in simulations performed to test the predictions of theory in the limit of small Kubo number turbulence.May 202
Development of microfluidic passive flow assays for point-of-care quantification of chronic kidney disease biomarkers in urine and serum
Get PDFChronic kidney disease (CKD) significantly affects people's health and life quality and presents a high economic burden worldwide. However, the existing diagnostic test methods remain complicated and cost-prohibitive.
This research addresses critical gaps in CKD diagnostics through the development of innovative microfluidic platforms for point-of-care (PoC) testing. We present complementary approaches targeting key CKD biomarkers: a passive flow microreactor for urinary creatinine measurement (uCR-Chip) and microfluidic devices for serum cystatin C (CYS-C) quantification.
The uCR-Chip employs a 2-phase pressure compensation technique, optimized observation window (OW), and channel network design to control fluidic mixing and chemical reactions precisely. A stable signal is achieved within 7 minutes, with the dynamic range up to 40 mM and a lower limit of detection of 0.521 mM. This performance meets clinical precision requirements and demonstrates acceptable recovery rates in artificial urine matrices, particularly at lower creatinine concentrations, making it highly amenable to integration with previously developed microfluidic urine albumin assays.
For CYS-C, recommended as a superior estimated glomerular filtration rate (eGFR) biomarker due to minimal influence from non-filtration factors like muscle mass, we developed a PDMS-based immunoturbidity chip enabling side-scattering optical measurement. We demonstrated that the CYS-C chip meets the clinical requirements for detection range and limits while integrated into a custom-developed reader for PoC applications. Validation studies using CKD patient samples demonstrated comparable agreement levels with the traditional well plate-based immunoturbidity assay test results, determining eGFR range across clinically relevant group criteria.
Together, these microfluidic platforms offer viable solutions for decentralized CKD assessment, providing potential technology for measuring various disease biomarkers with advantages in accessibility, speed, and precision compared to existing clinical methods.October 202
The north, the land, the snow goose: an interpretive framework for Goose Creek and Wapusk National Park
Get PDFThe importance of northern landscapes is widely recognized across various disciplines, including climate science, natural history, and landscape architecture. As climate change trends continue, the most immediate and severe effects occur in Arctic and sub-Arctic regions. The north is important due to its natural resources and as a part of the global climate system. However, northern landscapes are also important for their ecological diversity, cultural significance, and beauty.
This practicum explores the northern ecosystems of Wapusk National Park and Churchill, Manitoba, adversely affected by anthropogenic factors, including climate change and the exponential growth of the lesser snow goose population that breeds and nests in the fragile coastal salt marshes and sedge meadows. Over the past 50 years, these vulnerable landscapes have become degraded to the extent that revegetation may take centuries.
Protecting, preserving, and presenting endangered and damaged northern landscapes begins with education and awareness, environmental stewardship, and fostering a personal connection to the land.May 202
Factors Influencing Testes Size in the Cape Ground Squirrel (Xerus inauris)
Get PDFWhen males compete through sperm competition, selection favours an increased investment in sperm production to streghten the male’s probability of siring offspring when females multiply mate. This increased investment in sperm quantity results in large testes relative to the species’ size. Thus, testes size can be used as a measure of reproductive fitness in males experiencing intense sperm competition. Despite this relationship, studies investigating testes size have focused on interspecific variation, leaving the factors driving intraspecific variation in testes size an underexplored area of study. I investigated the influence of age, body condition, rainfall, parasite abundance and testosterone concentration on the testes size of Cape ground squirrels, a sciurid known to be under intense sperm competition. Data was collected from males trapped on SA Lombard nature reserve in South Africa between the years 2013-2024 and the influence of each factor on testes mass was assessed using linear regression. Testes mass was found to increase with both age and body condition and body condition also increased with age. While the energetic demands of spermatogenesis appear to shape the relationship between body condition and testes size, declining oxidative stress with age and a terminal investment strategy may drive enhanced testes investment in older individuals. Parasite abundance negatively affected testes size suggesting parasites remove resources from their host that would otherwise be allocated to reproduction. Rainfall and testosterone concentration did not affect testes size. The lack of relationships between rainfall and testes size may have occurred due to the limitations of this study, while testosterone's lack of impact on testes size may be caused by the low testosterone demands of a year-round breeding strategy. These findings aid in our understanding of the factors influencing reproductive success in males experiencing sperm competition and the selective forces shaping intraspecific testes size variation
Sustainable extraction technology using Deep Eutectic Solvents for producing fava bean protein isolates with improved functionalities
Get PDFThe fava bean is a nutritionally rich protein source, making it an ideal choice for producing protein ingredients. The limitations of conventional plant protein extraction methods have driven increasing interest in novel, sustainable green extraction technologies. Therefore, the main objective of this research study was to develop a novel protein extraction method using Deep Eutectic Solvents (DES) for producing fava bean protein ingredients with improved functionalities. First, the DES system was optimized for the protein extraction variables using the response surface methodology (RSM). The optimum conditions achieved indicated that the DES could produce a significantly higher protein yield (~65%) with similar protein content (~92%) to the conventional alkaline method (AE). It was revealed that DES extraction was also less prone to protein denaturation than AE. Owing to these properties of DES-extracted fava bean protein isolates (DES-FBPI), the functional properties, solubility, and emulsifying and foaming properties were greatly improved. Interestingly, the DES method produced high-quality proteins with significantly higher (>75%) protein digestibility-corrected amino acid score (PDCAAS), compared to the conventional methods. Moreover, the integrated approach, including ultrasonication and enzymatic pre-treatment-assisted DES protein extraction, further showed a significant increase in protein yield with improved functionality. Although DES is highly viscous, the addition of water in the DES system (0-100% wt%) demonstrated significantly reduced viscosity, thus significantly increasing protein yield. The alteration of physicochemical and structural changes of DES induced by the water substitution led to significant differences in the structure-functional properties of the extracted proteins, tailored to a specific food application. From the food application perspective, the behavior of fava bean proteins in the DES system is crucial when determining protein functionality, including gelation. In particular, the gelling capacity of DES-FBPI was a distinguishable characteristic, producing a strong, firm gel comparable to commercially produced soy proteins. Hence, DES extraction offers a valuable opportunity to replace soy-based foods with fava bean proteins as a potential strategy to reduce soy allergenicity. Overall, DES extraction presents a viable alternative to conventional methods, offering green benefits with potential scalability at the industrial level to upgrade the utilization of fava beans in value-added food formulations.University of Manitoba graduate fellowship (Ph.D)
University of Manitoba/James W. Barlow graduate fellowship
University of Manitoba/Alfred Rea Tucker Memorial Scholarship
University of Manitoba/Faculty of Graduate Studies Research Completion Scholarship
University of Manitoba/Garson N (Gerry) Vogel Memorial Award
University of Manitoba/Canadian Institute of Food Science and Technology Graduate Travel Award
University of Manitoba/Faculty of Graduate Studies Travel AwardOctober 202
Evaluating Nitrogen Utilization Strategies in Chlamydomonas reinhardtii
Get PDFNitrogen (N) is a common, yet essential macronutrient required for nucleic acid and amino acid synthesis for cell growth and biomass of photosynthetic eukaryotes which includes algae and plants. Understanding how organisms strategically use N for growth will allow development of economical use of N fertilizer being invested into croplands, which in return mitigates anthropogenic contribution to environmental pollution. This honours thesis explores N-use strategies by examining the N-sensing mechanisms within Chlamydomonas reinhardtii to investigate its necessity for optimal growth under N-limited and N-repleted conditions through comparative growth within individual N source provision of NH4Cl, KNO3, and urea. Using photobioreactor and nitrogen quantification experiments, I obtained biomass productivity data and residual N within the cultures, which allowed for an understanding of algal growth under various N-source concentration
conditions. Through a comprehensive data analysis of growth biomass OD and residual N concentrations, my study uncovered that there is a regulatory mechanism of C. reinhardtii that allows for a reduction in N consumption rate under extreme N limitation stress, which in turn allows the algae to shift its metabolic priorities to internal N-use. These insights contribute to the existing literature by highlighting the significance of the N-sensing mechanism within C. reinhardtii, for N-use strategies, discovering a temporal switch in metabolic function, and offering potential further investigations into how the algae prioritize cellular N contents for growth and cellular division. Ultimately, this study provides a deeper understanding of N assimilation and cellular use, paving the way for future research and developments in the field
The material semiotics of “heavy drinking” among young people in Taita-Taveta, Kenya: an ethnographic examination
Get PDFIntroduction: Alcohol consumption is a significant global public health concern. According to the World Health Organization, harmful alcohol use contributed to approximately 2.6 million deaths globally in 2019, accounting for 4.7% of all deaths that year. Young people, in particular, are disproportionately affected by the health and social consequences of harmful alcohol use. In Kenya, national statistics, local research, and news media reports consistently portray problematic drinking as an urgent public health issue requiring intervention. However, current public health interventions tend to prioritize individualistic, biomedical, and prohibitionist approaches that pathologize alcohol use, focusing on policing, restriction, and abstinence as primary interventions. These approaches fail to account for the complex socio-material and structural realities that shape alcohol consumption within localized contexts.
Methodology: In my dissertation research, I critically examine the persistence of problem drinking despite these interventions and explore the broader social, economic, and political realities that sustain it. Between July 2023 and March 2024, I conducted a multi-sited ethnographic study in Taita-Taveta County, Kenya. Drawing on material semiotics, I examine how alcohol functions as a socio-material actant, shaping and being shaped by human and non-human actors, including drinking spaces, regulatory frameworks, economic systems, and cultural practices. Through participant observation, in-depth interviews, and participatory material-semiotic geospatial mapping, I trace how alcohol consumption is enacted within dynamic networks of sociality, economic vulnerability, gendered norms, and regulatory governance.
Findings: I introduce the concept of Liquid Kinship to describe how alcohol consumption mediates social bonds by establishing relationships of care, reciprocity, and belonging while also reinforcing dependency, exclusion, and vulnerability. I also develop the concept of Liquid Fugitivity to capture how individuals within informal alcohol economies strategically evade regulation, negotiate risk, and adapt to economic marginalization and state surveillance.
Conclusion: My research findings demonstrate that problem drinking among young people is not just an individual pathology but a reality woven into broader socio-material assemblages. I recognize this complexity and argue for a paradigmatic shift in alcohol policy and practice. Policymakers must design and reform policies that reflect the lived realities of young people in Taita-Taveta and similar contexts, shifting away from punitive and prohibitionist approaches and toward structural, harm-reduction, and community-led strategies. Achieving this shift requires legalizing and regulating traditional brews, strengthening community-based harm reduction initiatives, expanding local economic opportunities, and reforming licensing frameworks to address corruption and socioeconomic disparities.University of Manitoba, Graduate Studies Thesis Completion Award
University of Manitoba Graduate Fellowship (UMGF)October 202
Thermal imaging technology for rapid in-vivo evaluation of carcass composition in growing-finishing pigs
Get PDFSelecting market hogs' antemortem is labour-intensive and time-consuming, involving evaluations based on weight and conformation. However, most hog markets pay the producer based on pork carcass merit, which is determined at postmortem by carcass leanness percentage. The objective of this study was to predict carcass traits and composition of live animals by using multispectral thermal imaging with computer vision models. A total of 243 finishing pigs (crossbred Large White × Landrace barrows and gilts; average body weight 122 kg) were used for that purpose. Three days before slaughter, dorsal images were captured using a multispectral camera (5–15 μm wavelength range). Once pigs were slaughtered, lean depth, fat depth and leanness percentage were obtained from hot carcasses using a Destron probe. After 24 hours postmortem, chilled carcasses were fabricated into primal cuts and analyzed for leanness percentage via dual-energy X-ray absorptiometry (DEXA). Images were preprocessed, and 238 were selected based on quality and complete data. Computer vision models were trained with data augmentation techniques to predict carcass traits and classify carcasses based on lean grade index (higher lean grade indexes > 109 scores; between 57.7 to 64.2% of leanness and 80 to 105 kg of hot carcass weight). Bayesian optimization was applied to fine-tune model hyperparameters. The models showed low performance in predicting individual carcass traits and composition variables with an (RMSE of 4.93mm, an ooSR2 of 0.04) for fat depth and (RMSE of 5.77mm, and an ooSR2 of -0.14) for lean depth. The classification model moderately distinguished high and low lean-grade indexes based on DEXA lean yield (F1 score: 0.73), while Destron assessments showed a lower F1 score (0.38). Multispectral imaging technology could enable producers to market hogs based on the best grid grade. Future research should focus on increasing sample size, and integrating additional measurements, like phenotypic (e.g., body weight, sex classification, feed efficiency, and age), and genomic data, (e.g., breed type, sire, and dam lineage) and advancing from 2D to 3D imaging to enhance model accuracy and reliability.Results Driven Agriculture Research (RDAR)
Animal Inframetrics
Alpha PhenomicsMay 202
Mediation practice in Nigeria: experiences from Abuja and Ondo with lessons from Ontario, Canada
Get PDFThis thesis examines mediation practices in Nigeria: its development, challenges and success, precisely within the judicial precinct of Abuja and Ondo, while drawing lessons from Ontario, Canada. The research explores extensively, the evolution of dispute resolution mechanisms in Nigeria, from traditional methods to the formal integration of mediation within the judicial system. Comparatively, the study analyses the legal frameworks, institutional structures, and operational challenges of court-connected mediation in Nigeria, particularly in Abuja and Ondo State.
The research provides a detailed overview of mediation's development in Nigeria, including the establishment of Multi-Door Courthouses and Alternative Dispute Resolution Centers. It examines the effectiveness of these institutions in resolving disputes and improving access to justice. The thesis also traverses the recent enactment of the Nigerian National Mediation Act (Arbitration and Mediation Act 2023) and its potential impact on mediation practices across the country.
In contrast, the study investigates Canada's mediation landscape, with a specific focus on Ontario's Mandatory Mediation Program (OMMP). It traces the evolution of mediation in Canada, highlighting the push for national legislation and the development of guidelines by the Alternative Dispute Resolution Institute of Canada (ADRIC). The research offers insights into the structure, implementation, and outcomes of the OMMP, offering useful lessons for Nigeria's evolving mediation system.
The thesis employs a comparative analysis to identify best practices and potential areas for improvement in Nigeria's mediation framework. It addresses key challenges facing mediation in Nigeria, such as inadequate funding rising from absence of Judicial autonomy, reluctance among legal practitioners to embrace ADR because of paucity of research in mediation and ADR, this poor knowledge results in low referral rates from judges and magistrates. Hence, the findings emphasize the pivotal role of judicial autonomy, adequate funding and comprehensive legal education in advancing effective court-connected mediation and ADR. By drawing on Canada's experiences, particularly the success of the OMMP, the study proposes recommendations for enhancing Nigeria's mediation practices.
This research contributes to the growing body of knowledge on alternative dispute resolution in Nigeria and offers practical insights for policymakers, legal practitioners, and stakeholders involved in the administration of justice. The findings and recommendations aim to improve the efficiency and effectiveness of mediation as a tool for dispute resolution within the Nigerian legal system.National Student Loans Service Centre (NSLSC)May 202
Fuzzy volatility networks for enhanced portfolio optimization and model risk forecasts for deep learning models
No full textThis thesis explores advanced statistical and deep learning models for volatility forecasting and network inference for enhanced portfolio optimization. In the domain of risk forecasting, traditional time series models along with machine learning and deep learning models are evaluated for volatility forecasting. These models are also used to generate model risk forecasts for deep learning models, offering an advanced framework to assess financial system stability. Furthermore, this thesis demonstrates the superiority of the neural network autoregressive model (NNAR) with forecast linear augmented projection (FLAP) over the autoregressive integrated moving average (ARIMA)
model with FLAP in forecasting multivariate price and volatility. This performance achievement leads to reduced forecast error variance. The thesis further introduces data-driven fuzzy volatility networks and nonlinear adaptive fuzzy adjacency matrices, which capture model uncertainty in volatility correlations and enable the construction of resilient network structures. These are employed in combination with clustering techniques, network-based community detection methods, and PageRank for portfolio construction, leading to diversified portfolios with improved cumulative returns. Another key innovation is introducing neuro correlation networks using nonlinear correlation measures derived from innovations of NNAR models. Dynamic price networks are used to account for the non-stationarity in financial time series, enabling improved insight into
market structure and systemic risk over time. Random matrix theory (RMT) is used to denoise covariance matrices, thereby improving the accuracy of estimation, demonstrating superior performance in portfolio optimization, especially with t-distributed returns. Moreover, the theorem of combined estimating functions, which introduces a new risk measure with a smaller variance, is studied and applied in both risk forecasting and portfolio optimization. Extensive simulations and empirical analysis using stocks, cryptocurrencies, and other assets validate the efficiency of these methods.October 202